Site Monitoring And Numerical Analysis Of Bedding Slope Sliding Scope In Badong Railway Station Of Yichang-Wanzhou Railway

Yichang-Wanzhou railway crosses mountains among eastern Chongqing and western Hubei, along which is high mountains, lofty peaks and widely scattered weak rocks. Since the line can not be available without going along the structure lines across the two sides of the valley, and bedding slope cutting occurs more than 60, with a length of about 15 km, most of which are steep slope cutting, while some are large-scale bedding slope, the project faces serious stability issue and the prevention of geological disasters. The length of bedding slope in Badong station of Yichang-Wanzhou railway is about 300 meters, they brush by the sliding-level and use piles to support against sliding, the designing unit estimated a length of 50 meters where needs support. This paper integrates monitoring and numerical analysis methods, and back analyzes the rock deformation parameters of slopes to calculate and verify the slope areas affected by excavation. Therefore, this paper has great practical value for engineering practice, and it is also an example for similar projects to refer to.In order to determine the affected areas by excavation on bedding slope in Badong station, the site is firstly monitored, and the content can be divided into landslide displacement field, seepage field and reinforcing effect. Site monitoring contains two phases, namely the construction period (lasts six months) and the latter period of half year.Through site monitoring of piles against sliding on the bedding slope in Badong station of Yichang-Wanzhou railway, the pile top horizontal displacement while it is stable after deformation can be obtained. According to the analysis and back analysis principle, using FLAC numerical analysis software, the corresponding grid to the site and constitutive model can be obtained, then fix other parameters in the site and back analyze the deformation parameters of carbonaceous shale dissection. Assuming that there is not any support after excavation, the potential impact range of the slide can be calculated by the deformation parameters from the back analysis.According to the above program and in the light of the site displacement data, through iterative optimization to minimize the error function, then revise the parameters until the optical value is approximated, and ultimately this paper attains a group of deformation parameters which conforms mostly to the carbonaceous shale slope dissecting in the site. Substituting the rock deformation parameters in the back analysis step into the FLAC model of the bedding slope excavated without support, the results show that: if there is not any support in the site after excavation, it will come with 18 meters tension crack area of horizontal length, extending backward along the excavation profile, and it will cause gradual damage to the slope without effective treatment.